Investigating a possible solution to the Cosmic Microwave Background Anomalies

The Cosmic Microwave Background (CMB) structure was hidden for many years due to instrumental limitations. Nowadays is no longer the case, we have strong theoretical and empirical arguments that the CMB has a wealth of scientific information on its temperature and polarization pattern. The extensive studies of this data have made possible to define the current cosmological model (LambdaCDM) with extreme precision. However, the diverse CMB measurement taken by WMAP and Planck satellite have shown some departures from our cosmological standard model, claim the presence of unexpected features (or anomalies) in the CMB at large angular scales. Even when many of these anomalies are not statistically significant (2 – 3 sigma level), many consider that their presence can open the window to explore new physics, probably related to the initial condition of the Early Universe. Motivated to find a common physical cosmological origin to these anomalies numerous detailed investigations have been carried on. A recent phenomenological model proposed by Hansen et al. 2019 which reproduces simultaneously six extensively studied anomalies and is based on the idea that non-Gaussianity may be the origin of these anomalies. Therefore, the goal of this thesis is to compute and characterise the trispectrum (the Fourier counterpart of the 4-point correlation function) associated with the toy model, there are two essential quantities that we aim to obtain the overall amplitude and the shape. Analysing these quantities allows us to associate specific information with different inflationary models or cosmological scenarios. The results of our trispectrum analysis can provide insights into primordial non-Gaussianity, which may be related to the initial conditions of the Early Universe. Additionally, it can offer further information about the physical model underlying the phenomenological model that reproduces the CMB anomalies.